The present invention relates to colored ink pens and more particularly to kits or systems, used typically by artists and the like, consisting of a plurality of pens of different colors for selective use by the artist. The invention is directed to improvements in such multi-color pen systems also providing for desirable economies of manufacture while providing certain conveniences of storage and use.
In a liquid ink pen of the type contemplated, a pen unit houses a reservoir for liquid ink and utilizes a capillary system for feeding ink to the writing point while enabling the reservoir to xe2x80x9cbreathexe2x80x9d in necessary ways. For example, as ink is used in the reservoir, air must be admitted to prevent formation of a vacuum. In addition, changes in temperature cause volume fluctuations in the air and liquid in the ink reservoir, which are accommodated by the capillary system. The relevant principles are well known and are described in, for example, the Wittnebert U.S. Pat. No. 3,951,555.
In accordance with the present invention, a multi-color pen system is provided in which there are multiple independent liquid ink pen units, each a complete, functioning pen which is of minimal structure comprising a nib and collector cartridge and a tubular receiving body. The collector element is received in an open lower end of the receiving body, and the upper portion of the receiving body, above the collector, forms an ink reservoir. The receiving body is a simple plastic molding, which is designed to be almost exclusively functional, without regard to appearance or other factors.
In conjunction with the plurality of pen units, the invention contemplates the use of a single tubular pen holder which attaches to the upper portion of the receiving body by means of screw threads or the like. Within the contemplation of the invention, of course, there could be more than one pen holder, but the invention contemplates that there should normally be only one and in any case significantly fewer pen holders than pen units.
Pursuant to a preferred embodiment of the invention, the tubular receiving body has a stepped configuration, being of somewhat greater diameter in its lower portion than in its upper portion. The somewhat larger lower portion receives the collector element and by that means mounts the nib and writing point at the forward end of the receiving body. An external connecting means is provided on the receiving body, with screw threads or the like to detachably engage a holder element. The holder element is arranged to be received over the upper portion of the receiving body to provide a comfortable grip for the pen. Preferably, the receiving body extends below the connector means such that the lower portion of the receiving body forms, in effect, an extension of the holder.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments of the invention and to the accompanying drawings.